I know, this is out of character for me! Just like when I did a Google image search for Digidesign NuBus cards and saw your avatar in the lineup. :lol:
I was going to link to info about these but had trouble remembering where I saw it. Here! http://www.cx5m.net/ When I discovered it the site maintainer broke the links because they claimed too many people were abusing bandwidth... but they seem to work now. Includes manuals, schematics, cartridge ROMs, and other helpful info.
No keyboard for mine yet, but supposedly the upgraded SFG05 synth in it can respond to MIDI. Also it seems easy to program its "toolbox" in BASIC for synth access, MIDI, and speech synthesis in Japanese. An excellent programmer such as yourself will have no problems with it.
As for the video out, the DIN jack can be readily adapted for RCA outs for composite video and mono sound (separate from the synth outs). I was hoping to do it last night but I was catching up on housework, reading, etc and it got away from me. Hopefully tonight I can get caught up with my immediate computer stuff.
There are many sites out there offering MSX ROMs! I am going to build a few cartridges with ZIF sockets for trying them out - after I verify that it even works in the first place.